This invention relates to a compressor. In more detail the invention relates to a free piston inertia compressor. Specifically the invention relates to a free piston inertia compressor which is useful in combination with a free piston Stirling engine as a refrigerant compressor in a gas fired heat pump. The invention also relates to a seal ring assembly for use therein.
Inertia or free piston pumps and compressors are old in the art, typical examples being shown in U.S. Pat. No. 3,198,425 granted Aug. 3, 1965, and the patents cited therein. By employing a free piston compressor, a compressor can be attached directly to the reciprocating motion of any device such as a power piston and the connecting rod/crank-shaft/bearing and seal system that would be required to connect the linear motion of a piston to the rotary motion of a conventional rotary compressor is not needed.
Thus free piston inertia compressors are particularly suited for use in combination with a free piston Stirling engine in a gas fired heat pump. In the gas fired heat pump, a free piston Stirling engine is the prime mover and this engine provides linear motion to drive directly the free piston vapor compressor for the refrigeration cycle. Incorporation of an inertia compressor with a free piston Stirling engine permits complete isolation of the Stirling engine working fluid from the ambient and from the refrigeration loop without the use of dynamic seals.